相关论文: Baby Universes Revisited

We investigate the fractal structure of $2d$ quantum gravity, both for pure gravity and for gravity coupled to multiple gaussian fields and for gravity coupled to Ising spins. The roughness of the surfaces is described in terms of baby…

We study quantum entanglements of baby universes which appear in non-perturbative corrections to the OSV formula for the entropy of extremal black holes in Type IIA string theory compactified on the local Calabi-Yau manifold defined as a…

We measure numerically the distribution of baby universes in the crumpled phase of the dynamical triangulation model of 4d quantum gravity. The relevance of the results to the issue of an exponential bound is discussed. The data are…

We measure the fractal structure of four dimensional simplicial quantum gravity by identifying so-called baby universes. This allows an easy determination of the critical exponent $\g$ connected to the entropy of four-dimensional manifolds.

We show that the surface roughness for $c<1$ matter theories coupled to $2D$ quantum gravity is described by a self-similar structure of baby universes. There exist baby universes whose neck thickness is of the order of the ultraviolet…

The validity of the Coleman mechanism, which automatically tunes the fundamental constants, is examined in two-dimensional and four-dimensional quantum gravity theories. First, we consider two-dimensional Euclidean quantum gravity on…

The dynamics of baby universes which are branched off in pairs from a large universe and whose respective members are entangled to each other has been studied in quantum gravity and string theory. It is shown that the probability measure…

We develop a model of $(1+1)$-dimensional parent and baby universes as macroscopic and microscopic fundamental closed strings. We argue, on the basis of understanding of strings from the point of view of target $D$-dimensional space-time,…

Emission of hard microscopic string (graviton) by an excited macroscopic string may be viewed as a model of branching of a $(1+1)$-dimensional baby universe off large parent one. We show that, apart from a trivial factor, the total emission…

A set of physical operators which are responsible for touching interactions in the framework of c<1 unitary conformal matter coupled to 2D quantum gravity is found. As a special case the non-critical bosonic strings are considered. Some…

We argue that the holographic description of four-dimensional BPS black holes naturally includes multi-center solutions. This suggests that the holographic dual to the gauge theory is not a single AdS_2 times S^2 but a coherent ensemble of…

We apply the recently proposed transfer matrix formalism to 2-dimensional quantum gravity coupled to $(2, 2k-1)$ minimal models. We find that the propagation of a parent universe in geodesic (Euclidean) time is accompanied by continual…

We discuss Euclidean geometries in AdS$_3$ whose Lorentzian slicing gives rise to closed baby universes with a spatial geometry given by genus $g\geq 2$ surfaces. Our setup only involves a two-dimensional holographic CFT defined on a higher…

We examine the idea that our universe began as a baby universe and show that this is feasible in a gauged $U(1)_{B-L}$ extension of the Standard Model with the classically conformal principle. For the first time, we define a measure to…

A real space renormalization group technique, based on the hierarchical baby-universe structure of a typical dynamically triangulated manifold, is used to study scaling properties of 2d and 4d lattice quantum gravity. In 4d, the…

The semi-classical nature of braneworld cosmological models does not account for any quantum gravitational effects. In this letter we use the gauge/gravity correspondence to argue that quantum string corrections cannot be ignored in any…

We consider equilibrium models of spherical boson stars in Palatini $f(\mathcal{R})=\mathcal{R}+\xi \mathcal{R}^2$ gravity and study their collapse when perturbed. The Einstein-Klein-Gordon system is solved using a recently established…

We explore a simple toy model of interacting universes to establish that a small baby universe could become large ($\gg$ Planck length) if a third quantization mechanism is taken into account.

Baby universes (inflationary or non--inflationary) are regions of spacetime that disconnect from the original ambient spacetime, which we take to be asymptotically flat spacetime. A particular kind of baby universe solution, involving…

We provide detailed evidence for the claim that nonperturbative quantum gravity, defined through state sums of causal triangulated geometries, possesses a large-scale limit in which the dimension of spacetime is four and the dynamics of the…